Some types of power supplies and other electronic equipment connect a plurality of power transistors in parallel to obtain optimum total current-carrying capacity for the system. This is done where the total current to be conducted is greater than the current-carrying capacity of one transistor. However, in such circuits, for the usual case of equally-rated transistors, it is important to share the total current substantially equally between all of the transistors. In the more general case, where dissimilarly-rated transistors might be paralleled, it is important to share the total load current in proportion to the various transistor ratings. Further, it is very desirable to be able to deal with, in the most general case, of up to an indefinite number, N, parallel-connected transistors, while still being able to obtain the desired sharing of the total load.
Although circuits are known for performing this function, none appears to be as simple, efficient and flexible as the circuit of the present invention.